Weird rash between/under breasts

Brittany

Hello, I have had this weird rash under my breasts for quite some time now and I’m not sure what it is. It does not itch or burn. Honestly I can’t tell it’s there unless I see it. I was just at my doctor today for an unrelated visit and totally forgot to mention it 🤦‍♀️. I have rather large breasts and my thought is that it is a yeast infection. Anyone have any other ideas and remedies? Sorry for the TMI pic.